Mr Gove has been giving evidence before MPs after Welsh education minister Mr Andrews said some GCSE papers must be remarked due to disputes over the accuracy of the marking.

School heads suggested that exams had been marked harshly after Ofqual told exam boards to limit grade inflation.

Mr Gove said that simply raising grades would ‘undermine confidence’ in GCSE qualifications and branded Mr Andrews ‘irresponsible and mistaken’.

On Tuesday the WJEC exam board was ordered to regrade all GCSE English exams taken in Wales, but a similar reappraisal was blocked by Ofqual in England – meaning that the two countries’ students could end up with different grades for the same marks.

Mr Andrews previously said Welsh pupils should not have to ‘live with the consequences of having been awarded what, in all likelihood, is the wrong GCSE grade’.

Students and parents are concerned that this summer’s GCSEs were not marked accurately (Picture: PA)

Exam boards told reporters that grade boundaries had been altered significantly halfway through the year, being moved by as much as 10 marks.

Mr Gove rejected the idea of launching an independent inquiry, but said that individual students can appeal their marks and reiterated his view that the structure of GCSEs be overhauled.

Glenys Stacey, head of Ofqual, appeared before the committee yesterday to deny claims of unfairness or political interference in grading.